(Second attempt to post) Matthew Dempsky wrote:
I'm curious if there's any way to get code like the following to work:
boost::any a = char(10); int i = boost::any_cast<int>(a);
You can customize boost::dynamic_any::any. Example: #include <string> #include <stdexcept> #include <iostream> #include <boost/mpl/list.hpp> #include <boost/type_traits/is_convertible.hpp> #include <boost/dynamic_any/any.hpp> #include <boost/dynamic_any/function.hpp> #include <boost/dynamic_any/operations.hpp> // helper template<bool IsConvertible> struct convert_to_int { template<class T> static int do_convert(const T & value) { int result = value; return result; } }; template<> struct convert_to_int<false> { template<class T> static int do_convert(const T & value) { throw std::runtime_error(std::string("no convertion to int")); } }; // any to int convertion struct to_int : boost::dynamic_any::function< to_int, // curiously recurring pattern int (const boost::dynamic_any::arg &)> { template<class T> int call(const T & value) { typedef convert_to_int< ::boost::is_convertible<T, int>::value> converter; return converter::do_convert(value); } }; // customized any typedef boost::dynamic_any::any<boost::mpl::list< to_int, boost::dynamic_any::to_ostream<char> > > my_any; int main() { my_any a('a'); my_any b(3.14); std::cout << a << " -> " << to_int()(a) << '\n'; std::cout << b << " -> " << to_int()(b) << '\n'; } CVS access to the library: $ cvs -d:pserver:anonymous@cvs.sourceforge.net:/cvsroot/cpp-experiment login $ cvs -z3 -d:pserver:anonymous@cvs.sourceforge.net:/cvsroot/cpp-experiment co dynamic_any -- Alexander Nasonov Remove - m y c o p from my e-mail address for timely response